Refrigeration



Nov. 26, 1929. s, M BCKSTRM 1,736,871

REFRIGERATION Filed Mayv 4, 1927 3 Sheets-Sheet l l N V E N TO R? Nov. 26, 1929. s. M. BCKSTRM REFRIGERATION Filed May 4, 1927 3 Sheets-Sheet lNvENT R J 4J/m4- 241%/ ATTORNEY NOV. 26, 1929. s, M, BCKSTRM 1,736,871

REFRIGERATION Filed May 4, 1927 5 Sheets-Sheet 3 Jg. 5- M2 Vfxgsym;

:www ls ATTOR N EY Patented Nov. 264, 192g UNITED STATES PATENT OFFICE SIGURD MATTIAS BCKSTRM, 0F TOCXHOLM, SWEDEN,` ASSIGNOR TO ELECTROLUX SERVEL CORPORATION, OF NEW YORK, N. Y., A CORPORATION 0F DELAWARE REFRIGERATION Application led May 4, 1927, Serial No. 188,652, and in Sweden May 22, 1926.

My invention relates to the art of refrigeration and particularly to absorption apparatus which is used to refrigerate vehicles, as. for instance, refrigerator cars on railroads.

One of the objects of my invention is to provide a system of automatic regulation whereby the heat supplied to the generator of the absorption system is varied in accordance with thespeed of the vehicle.

lVheu a mechanical refrigerating system of any type is used on a vehicle it is necessary to cool the heat giving parts of the apparatus by air. as it is dilcult` to carry an otherwise necessary and comparatively large supplyI of cooling fluid, for instance water. lfVhen air is used as a cooling medium its effect, generally and to a large degree. depends upon the speed of the car. Thus at low speeds and particularly when the car is stationary, very little cooling effect will be obtained due to the very greatly reduced velocity of the air past the parts to be cooled. If, under these conditions, heat is continually supplied to the generator, little or no refrigerating effect will result, While, on the contrary, the apparatus as a whole is apt to become heated and even radiate heat instead of absorbing heat from the interior of the refrigerator car. In order to prevent this heating I propose to reduce the heat supplied to the generator as the speed of the car decreases so that at all times there will exist the proper relation between this heat supplied and the cooling effect of the air. y

As is readily appreciated, the cooling effect of the air is dependent, not alone upon the speed of the vehicle, but also to a greater or less extent upon the velocity of the wind. That is, the cooling effect is dependent upon the velocity of the air past the parts to be cooled. In other words, approximately the same cooling effect is obtained when a stationary car is exposed to wind blowing at the rate of forty miles an hour as when a car is traveling forty miles an hour through calm air. In one embodiment of my invejntion, I make the automatic regulation of the heat supply dependent upon the velocity of the air relative to the car.

These and further objects and advantages ot' my invention will be apparent from the following description and accompanying drawings, of which:

Fig. 1 shows a more o r less diagrammatic illustration of my invention;

Fig. 2 is an elevational View of apparatus compartment 11 to which air is admittedv through an opening 12 in the bottom of the car. This air and the products of combustion resulting from gas burner 13 pass from compartment 11 through conduits 14 and 15 forming a chimney or fiue. Burner 13 serves to heat a Vapor generator 16 which is also withm compartment 11. A conduit 17 connects the upper part of generator 16 with a rectifier 18 which is placed Within a compartment 19. Air enters compartment 19 througha conduit 20 and passes therefrom through conduit 15. A conduit 21 connects rectifier 18 with a condenser 22 which is located upou the roof of the car. A conduit 23 connects condenser 22 with the up er part of an evaporator 24 which is placed) within the space to be cooled. Evaporator 24 is provided with fins 25 in order to obtain a large heat transfer surface.

Evaporator 24 is placed at a somewhat higher level than absorber 26. Conduit 27 connects the bottom of evaporator 24 with the lower part of absorber 26 while a conduit 28 connects the upper parts of these vessels together. A cooling jacket 29 partially surrounds absorber 26.

A conduit 30 connects the upper part of jacket 29 with a radiator 31 located upon the roof of the car while a conduit 32 connects the other end of radiator 31 with the `bottom of jacket 29. This packet 29, radiator 31 and conduits 30 and 32 comprise a closed system which contains a cooling fluid such as water. The water in jacket 29, upon becoming heated circulates upwardly through conduit 30, is cooled in radiator 31 and passes downwardly through conduit 32 and is again heated in jacket 29.

A conduit 33 communicates with the bottom of absorber 29 and passes for some distance within a larger conduit 34, is made in the form of a coil 35 and finally communicates with the upper part of generator 16. A conduit 36 connects the lower part of generator 16 with one end of outer conduit 34 while a conduit 37 connects the other end of conduit 34 with the upper part of absorber 26.

Burner 13 is supplied with through a conduit 38 from a replaceab e drum 39. A valve 40 is interposed in conduit 38, and regulates the as ilow therethrough. An arm 41 is rigi y attached to the spindle of valve 40 and pivotally connected to lever 42 at 43. Lever 42 is pivoted at 44 and has a forked end 46 which engages a circumferential slot 47 formed in a collar 45. Collar 45 is slidably mounted on a vertical shaft 48 and is free to move in a vertical direction thereon under the inlluence of the centrifugal force exerted by balls 49 after the nature of fly ball governors. A bevel gear 50 mounted on the lower end of shaft 48 engages a similar bevel ear 51 which is mounted on the car axle 52. alve 40 is so designed that it is closed by clockwise rotation of its valve spindle. Thus it is readilyseen that an increase in the speed of the car causes collar 45 to be raised, which in turn causes lever 42 to pivot in clockwise direction about pivot 44 which rotates arm 41 in counter-clockwise direction which in turn opens valve 40' to a greater extent. Conversely, a reduction in the speed causes valve 40 to be closed to a greater extent.

An alternate method of operating valve 40, depending solely upon the velocity of the a1r relative to car 10, is shownin Figs. 2 and 3. The device consists of a plate 53 pivotally mounted on the outside of the car wall 60, as at 54. To an arm 55 is fastened one end of a tension coil spring 56, the other ,end of which is secured to the adjacent face of plate 53. An arm 57 is rigidly attached to plate 53 in such a manner as to be caused to pivot about 54 by movement of the plate. An arm 58 is pivotally connected to arm 57 at 59, passes through an aperture 61 in wall 60 and is pivotally connected at 62 within the car to an arm 63. Arm 63 is rigidly attached to the spindle of valve 40. Valve 40 is designed to open when the spindle is rotated in a clockwise direction when viewed as inA Fig. 3. Assuming the car to move in the direction of the arrow in Fig. 3, the difference in the velocities of the car and the surrounding air causes the air to exert a force tending to rotate plate 53 clockwise against the tension of spring 56. This movement is transmitted through arms 57, 58 and 63 and opens valve 40. If the force exerted on plate 53 by the air decreases due to a decrease in the relative velocity of the air with respect to the car, due in turn to a decrease in the speed of the car, a change in the velocity of the wind, or afcombination of the two, plate 56 is rotated in a counter-clock wise direction and closes valve 40 to a greater or less degree. y

The absorption apparatus operates as follows: A solution consis i f of a refrigerant, for instance ammonia, disso ved in an absorbing medium, for instance w ter, is heated in vapor generator 16 by gas burner 13. This application of heat serves to drive ammonia out of solution as a vapor which passes upwardly through conduit 17 to rectifier 18. In rectifier 18 any water vapor is condensed and runs back to the generator.A The now dry vaporous ammonia passes through conduit 21 to condenser 22 where it is condensed to a liquid and runs downwardly'through conduit 23 to the upper part of evaporator 24.

In evaporator 24 the ammonia comes in intimate contact with a gas inert with respect to ammonia, for instance hydrogen, which is introduced through conduit 28. The ammonia evaporates in the presence of, and di'uses into the hydrogen and roduces refrigeration in known manner. he vaporous mixture of ammonia and hydrogen thus formed passes downwardly through the evaporator and through conduit 27 to the lower part of absorber 26.

In the absorber the mixture comes in intimate contact with a solution which contains f but a relatively small percentage of ammonia and which is introduced through conduit 37. The ammonia is absorbed'in the water and the lighter hydrogen passes upwardly through the absorber and through conduit 28 to the upper part of evaporator 24. The heat generated by the absorption process is carried away by the cooling medium which circulates through jacket' 29, conduit 30, radiator 31 and conduit 32.

The stron solution formed in the absorber passes there rom through conduit 33. In coil 35 it is heated. by .burner 13 and raised by the well known thermo-siphonic action to the upper part of generator 16. In the generator the ammonia is once again driven out of solution and the weak solution passes downwardly therethrough and through conduits 36, 34 and 37 to the upper part of absorber 26. In

conduit 34 the hot weak solution gives up heat to the cool strong solution in conduit 33.

In Figs. 4, 5 and 6 are shown a preferred form of the invention. The car 10 is lined with a suitable insulating material 70. A lateral space 71 extends for some distance along one side of the car. Louvres 72, shown more in detail in Fig. 6, are formed at either end of compartment 71 and serve to cause a current of air to pass through compartment 71 when the car is in motion. Within compartment 71 is situated the generator 16, rectifier 18, condenser 22, a portion of a gas heat exchanger 73, absorber 26, radiator 31 and a liquid heatexchanger consisting of conduit 33 within conduit 34. Generator 16 and the liquid heat exchanger are surrounded by a suitable heat insulating material 74. Generator 16 is divided into a main generator 75 and an auxiliary generator 76 by the partition 77. Auxiliary generator 76 performs a function similar to that performed by coil 35 in Fig. 1. A conduit 78 extends from within auxiliary generator 76 and communicates with the upper part of main generator 75. A pocket 79,extends centrally through auxiliary generator 76 and for some distance within main generator 75. Within pocket 79 is located an electrical heating element 80.

Heating element 80 isrelectrically con-4 nected by means of-a pair of conductors 81 with a single phase alternator 82 mounted underneath the frame of the car. Electric generator 82 is driven by a belt 83 from a pulley 84 mounted on axle 52. Conductors 81 also connect alternator 82 with a single phase motor 85. Motor 85 employs a split phase winding to obtain starting torque and hence rotates in a given direction and this direction is independent of the direction of rotation of alternator 82. A fan 86 is mounted on the armature shaft of electric motor 85 and serves to induce a draft downwardly past evaporator 24 which is within a compartment 87. Comparatively warm. air from the upper part of the car passes into compartment 87 through an opening 88, is cooled y contact with evaporator 24 and is forced out by fan 86. Air circulation is thus main'- tained Within the major cooling space of the car. A

The heating effect produced by electrical heating element 80 is dependent upon the speed at which alternator 82 is rotated. Thus the greater the speed of the train, the greater is the heating effect on generator 16 and hence a greater refrigerating effect is produced in evaporator 24. Likewise the s eed of fan motor 85 depends directly on t e speed of alternator 82. Thus the greater the refrigerating effect, the greater is the rate at which air is circulated past evaporator 24, which, obviously', is to be desired.

Although the principles involved in the operation of the absorption apparatus shown in Figs. 4 and 5 are similar to those in accordance with which theapparatus shown in Fig.

1 operates, the mode of operation of the former will be briefly outlined as there are some variations in details. Vaporous ammonia passes upwardly from main generator 7 5 through conduit 17 to within rectifier 18 where any entrained water vapor is condensed due to the cooling effect of liquid ammonia contained in U-s a ed member 89, one leg of which extends wit in rectifier 18. The dry ammonia vapor passes from the top of rectifier 18 into condenser 22 where it is liquefied by the cooling action of the air passing through compartment 71 due to the motion of the car. Condenser 22 may be provided with radiating fins, if desired. The liquid ammonia thus formedv passes into U- shaped member 89. From member 89 the liquid ammonia flows by gravity through a conduit 90 to the upper part of evaporator 24. In the evaporator the liquid ammonia is distributed over a series of disks 91 where it comes in intimate contact with a gas inert with respect to ammonia, for instance hydrogen, which is introduced through a conduit 92. The ammonia evaporates in the presence of, and diffuses into the hydrogen in known manner and a drop in temperature takes place which produces refrigeration.

The gaseous mixture of' ammonia and hydrogen thus formed in evaporator 24, having a greater specific weight than the hydrogen which is admitted near the top, passes downwardly therethrough and through a conduit 93 to space 94 included in the more central portion of heat exchanger 73 between tube heads 95 and 96. From space 94 the gaseous mixture passes through a conduit 97 to the lower part of absorber 2'6. In the absorber the mixture comes in intimate contact with water which has but little ammonia in solution and which is admitted to the upper part of absorber 26 through conduit 37.

This water absorbs the ammonia gas, and the lighter hydrogen, thus freed from the mixture, passes upwardly through absorber 26 and through a conduit 98 to a space 99 formed in one end of heat exchanger 73. From space 99 the hydrogen passes through tubes 100 to a space 101 formed in the other end of heat exchanger 73. From space 101 the hydrogen passes through conduit 92 to the upper part of evaporator 24. In heat exchanger 73 the low temperature of the gase-v ous mixture of ammonia and hydrogen in space 94, which has just left the evaporator, is utilized to pre-cool the hydrogen in tubes 100 and the liquid ammonla in conduit 90 before they enter the evaporator. Liquid which may tend to collect in spaces 99 or 101 passes therefrom through capillary parts 102 and 103 respectively into space 94 and thence through conduit 97 to absorber 26.

The heat resulting from the absorption process is carried away by the cooling Water, or other medium, in jacket 29. This water, upon being heated, rises through conduit 30 to radiator 31 which is cooled by the air passing through compartment 71. Radiator 31 ma be provided with radiating fins, if desire The water cooled in radiator 31 passes downwardly therefrom through conduit 32 to the lower part of jacket 29.

The strong solution of ammonia in water formed in absorber 26 asses therefrom through conduit 33 to auxiliary generator 76. The application of heat to the liquid in the auxiliary generator results in the formation of vapor. This vapor passes upwardly through conduit 78 to main generator 75 and carries with it slugs of liquid. In the gen` erator the ammonia is again driven out of solution and the weak solution passes downwardly therethrough and through conduit 36 to one end of the outer conduit A34a From the other end of conduit 34 the weak solution passes through conduit 37 to the upper part of absorber 26. The hot weak liquid in outer conduit 34 gives up heat to the cool strong liquid in inner conduit 33. The weak solution is further cooled by coming in heat exchange relation with cooling water in water jacket 29 as a portion of conduit 37 is within this jacket.

While I have shown and described more or less specific forms of my invention, it is to be understood that variations in the embodiment thereof are contemplated and fall within its scope. For instance, the apparatus may be installed in other types of vehicles, partielllarly automobiles. and controlled in a manner similar to that disclosed without departing from the spirit of the invention.

Y Having thus, described my invention, what I claim is 1. A refrigerator car having walls forming a major cooling space and a lateral space, a vapor generator in said lateral space, y a heater for said generator, elements connected to said generator forming a refrigerating system including an evaporator in said major space and a heat rejecting element in said lateral space, louvres for circulating air through said lateral space, and means responsive to the speed of the vehicle for controlling the heatin e'ect of said heater.

f2. A re rigerator car havingwalls forming a major cooling space and a lateral space, a vapor generator in said lateral space, an electric heater for said generator, elements connected to said generator forming arefrigerating system including an evaporator in said major space and a condenser arranged te be cooled by air outside said major space, a compartment forming member surrounding said evaporator havingopenings for circulation of air, a fan arranged to circulate air throu h said compartment,an electric `motor for driving said fan, an axle for said car, an electric'generator driven by said axle and electric connections between said electric generator, said electric motor and said electric heater.

3. A refrigerator car having walls forming a major cooling space and a lateral space, a vapor generator in said lateral space, an electric heater for said generator, elements connected to said generator forming a refrigerating system including an evaporator in said major space and a condenser arranged to be cooled by air .outside said major space, a compartment forming member surrounding said evaporator having openings for circulation of air a fan arranged to circulate air through said compartment, means responsive to the speed of said car for drivin said fan, said means acting to rotate said an in a given direction irrespective of the direction of motion of said car.

4. A refrigerator car having walls forming a major cooling space and a .lateral space, a vapor generator in said lateral space, an electric heater for said generator, elements connected to said generator forming a refrigerating system including an evaporator in said major s ace and a condenser arranged to be cooled y air outside said major space, a compartment forming member surrounding said evaporator having openings for circulation of air, a fan arranged to circulate air through said compartment, a single phase unidirectional electric motor for driving said fan, an axle for said car, a Single phase alternator driven by said axle, and electric connections between said alternator, said electric motor and said electric heater.

5. A refrigerator car, walls forming a cooiing space in said car, a fan for causing air circulation in said cooling space, means to transform linear motion of said car into rotor motion for driving said fan, said means acting to cause said rotary motion in a given direction irrespective of the direction of said linear motion of said car.

6. A vehicle comprising a refrigerating apparatus including a generator, a condenser, an absorber and an evaporator interconnected to form a systemthe parts being arranged so that movement of the vehicle'causes a current of air for cooling the condenser and absorber, a heater for heating the generator and means operating to decrease the heating effect of said heater on decrease of speed of said vehicle. 0

7. A vehicle comprising a refrigerating apparatus including a generator, al condenser, an absorber and an evaporator interconnected to form a system, the parts being arranged so that movement of the vehicle causes a current of air for cooling the condenser and absorber, a heater for heating'the generator, an axle for said vehicle, an electric generator driven by said axle and electric connections between said heater and said electric generator.

8. Refrigerating apparatus comprising .i generator, a condenser, an absorber and an evaporator interconnected to form a system,

means to create a current of air for cooling the condenser, means to suppl heat to the generator an'd means to vary e supply of eat to the erator in accordance with the s eed of e first mentioned means.

9. efrigerating apparatus comprising a generator, a condenser, an absorber and an evaporator interconnected to form a system, means to create a current of air for cooling the condenser and absorber, means to supply heat to the generator and means to v the sup 1y of heat to the generator in accor ance wit the speed of the irst mentioned means.

10. Refrigerating apparatus comprising a generator, a condenser, an absorber and an evaporator interconnected to form a system, means to suppl heat to the generator and means to simu taneousl increase the condenser cooling eiect an the supply of heat to the generator.

In testimony whereof I hereunto ax my signature.

SIGURD MATTIAS BCKSTRM 

